68 Descriptions of N'evj, 



Family Ceibrilinidje. 



Crihrilina monoceros, Busk, sp. 



This is a common and somewhat variable species, and it 

 seems to me that two distinct forms have been confused 

 together. The true G. monoceros is that described and 

 figured by Busk, and also in the Zoology of Victoria. The 

 zooecia are large, with large foramina, the margins of which 

 are thickened. The mouth is large, and the lower lip raised 

 into a central, pointed process. In some specimens there 

 are no oral spines, while in others there is a single spine on 

 one side, articulated close to the mouth, and really within 

 the peristome when that is developed. There are occa- 

 sionally two or three thin furcate spines on the upper 

 margin of the mouth, and the lateral oral spine is some- 

 times similarly terminated. The avicularia are frequently 

 wanting, or may be numerous and vary much. In some 

 specimens they are scattered and small, close to the sides of 

 the zooecia, with sharp mandibles, while in others they are 

 very large, with large, acute or spatulate mandibles, or 

 occasionally small with blunt mandibles. They are also 

 found of small size, sessile on eminences round the mouth. 

 A small avicularium is sometimes found surmounting the 

 mucronate elevation of the lower lip. 



Crihrilincc acanthocevos, n. sp. Plate II., fig. 4. 



Zoarium adherent. Zooecia with large foramina ; mouth 

 large, lower lip straight, with no mucro ; a large spine, very 

 long, and with sharp secondary spines or prickles directed 

 forwards, articulated immediately below the lip and to one 

 side; frequently a large avicularium, with triangular 

 mandible at each side of the mouth towards the angle. 

 Ooecia sub-immersed, surface with a thickened band, above 

 which it is marked with cribriform depressions similar in 

 form to the foramina of the zooecia. 



Port Phillip Heads ; Portland, Mr. Maplestone. 



This form differs from G. monoceros, chiefly in the 

 following points : — The lower lip is always straight, and 

 never developed into a mucro; the foramina are smaller, the 

 ooecium is somewhat different in its appearance, and especi- 

 ally in the situation of the oral spine. In G. Quonoceros it 

 is always situated at one side of the mouth, close to the 

 margin, above the angle, and is enclosed within the peristome- 



